A lawsuit is charging Chicago Public Schools with intentionally withholding public records regarding the firing of former principal Troy LaRaviere, known as one of Mayor Rahm Emanuel’s strongest critics.

Nick Burt filed a Freedom of Information Act lawsuit against CPS on Wednesday in Cook County Circuit Court. The suit states that CPS “willfully and intentionally” did not respond to Burt’s FOIA requests, not questions from the Attorney General’s office; it seeks records from his final, narrowed request made in May.

LaRaviere, former principal of Blaine Elementary School, was fired one month after he criticized Mayor Emanuel in a campaign ad for U.S. Sen. Bernie Sanders, according a statement from Burt. LaRaviere was elected president of the Chicago Principals and Administrators Association after his firing, the Chicago Sun-Times reported earlier.

Less than a week after the firing, Burt filed a FOIA request seeking documents relating to LaRaviere, Blaine Elementary and Bernie Sanders. His initial request was acknowledged by a CPS FOIA officer. Later, the request was denied because it was “unduly burdensome to Chicago Public Schools,” the suit said.

Burt was asked to narrow the scope of his request, which he did, but it was denied again in May. Burt narrowed his request again, but did not receive any response, even after multiple phone calls and emails to CPS regarding his revised request, the suit stated.

In June, Burt submitted a Request Review to the Illinois Attorney General’s Public Access Counselor. In response, an assistant attorney general wrote a letter to a CPS assistant general counsel inquiring about the status of Burt’s FOIA request. But through August, neither the attorney, nor CPS had responded. In a final attempt, Burt sent a letter to the attorney demanding a response, but it also went unanswered, according to the suit.

“Government agencies stonewall the public because they think they can get away with it,” Burt said in a statement. “They can’t. If CPS is terminating educators because they are critical of the mayor’s wasteful and ineffective school privatization agenda, the public has a right to know.”